First of all, China's goals for Japan are very clear. 1. Own up to what was done in WWII instead of changing textbooks to hide them (only from Japan's own children, making them seem ignorant in the world). 2. Stop returning to a shrine to honor war criminals; if you can't stop returning to a shrine that you say honors all of Japan's warriors through time, then take the war criminals out. It's really not that complicated.
Secondly, how is it China's responsibility to set an example for Japan to welcome friendlier relations in the future??? That is the responsibility of the victim??? To the criminal that doesn't even recognize his crimes?? I understand what you are saying; China could be the bigger man because it is so powerful and Japan is in such a sullen state, but never is it the responsibility of the victim to try to bury the hatchet and seek friendly relations with the perpetrator, who won't even admit to a crime.
Japan, at this point, is too deep into a corner to come out and move freely.
1. It feels so vulnerable and threatened by China because of China's rising strength and Japan's relative and increasing weakness. It is threatened by China's existence and it is haunted by its own past. "Who wouldn't want to destroy me after what I'd done to them? I can only escape this by keeping them weak." The only way for China to mitigate this would be to become weaker, which, I think we all know, is a thought for laughing only.
2. Japan is so covered in shame from what had happened since WWII. All those war crimes, still defeated. Was the shining star of Asia, head and shoulders above everyone else, now, a declining economy that grovels for protection from the neighbor it looked down upon the most. From world power to militarily colonized. The, from rising economy to gutted by its own master. Japan's just in such a bad place, it doesn't want to open up. Imagine if you got mugged, raped by another man, your car stolen, fired from your job, parents died in building crash, dumped by your wife, who took your house and kids, all in the last 3 days. You'd probably just want to lie in bed staring at the ceiling rather than go out there fixing things.
3. It is militarily colonized by the US. The US doesn't want war between China and Japan but certainly doesn't want to see them hugging like buddies either, because that would de-legitimize America's military presence in Japan. Everyone says it's to defend against North Korea, but we all know, the second China's military is deemed no longer a threat to Japan, that's when every Japanese wants the US military out, not that they could manage it...